Abstract
Quantitative histochemical analysis of the internal thoracic artery (ITA) and right gastroepiploic artery (GEA) was performed using microspectrophotometry. Arterial specimens from eight patients who underwent coronary bypass grafting using both ITA and GEA grafts were examined. There were seven men and one woman with a mean age of 60 years; ranging from 36 to 73 years. Concerning risk factors, 4 patients had hypertension, 3 had hypercholesterolemia and 2 had diabetes mellitus. The degree of intimal hyperplasia was calculated as follows; Intimal hyperplasia (%)=(I/I+M)×100 (I: area of intima, M: area of media). Quantitative histochemical analysis (smooth muscle cells, elastin, collagen and mucopolysaccaride) of arterial graft was measured by means of microspectrophotometry. Pieces of both the ITA and GEA grafts were obtained immediately before grafting. Each sample was stained with Azocarmin G, Weigert, van Gieson and Alcian Blue stains to identify smooth muscle cells, elastin, collagen and mucopolysaccaride, respectively. Intimal hyperplasia was significantly greater in GEA than ITA grafts (25.3 ±8.7% versus 6.8±3.5%, respectively; p<0.01). In quantitative histochemical analysis of the arterial grafts, the volume of smooth muscle cells was also significantly higher in GEA than ITA at both the intima (ITA; 38.8±7.9%E, GEA; 52.5±7.6%E, p<0.01) and media (ITA; 49.6±6. 5%E, GEA; 59.5±8.2%E, p<0.05). No significant differences in elastin, collagen or mucopolysaccaride content were observed. The greater amount of smooth muscle in GEA grafts may be one reason why the magnitude of intimal hyperplasia was greater in GEA than ITA grafts. Long-term follow-up is necessary to determine the course of atherosclerotic change in arterial grafts.
